Depression or prodromal fronto-temporal dementia?

Introduction. Frontotemporal dementia (FTD) is a rare neurodegenerative disease, occasionally late onset, whose prevalence is underestimated especially in the geriatric population. The initial symptoms can be confused with some psychiatric disorders, such as depression, so the differential diagnosis may require careful investigations. Here we report the case of a 75 years old patient presenting with severe anxiety symptoms, initial social withdrawal and mild cognitive impairment. Materials and methods. Longitudinal observational clinical study of 3 years. The patient underwent three successive cognitive assessments that included the Mini Mental State Examination (MMSE) and a battery of neuropsychological tests, imaging studies of the brain with a computer tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) and genetic analysis of a few possible mutations involved in FTD (C9ORF72, progranulin). Results. The results after the first visit showed a picture of non amnesic single cognitive domain (dysexecutive) Mild Cognitive Impairment (MCI) associated with anxious-depressive symptomatology. The initial neuroimaging demonstrated fronto-temporal cortical atrophy with mild enlargement of the frontal horns of the lateral ventricles, and moderate glucose hypometabolism of bilateral prefrontal cortex. Genetic tests were instead negative. These data were suggestive of a diagnosis of prodromal FTD. However, in the three years follow-up, following a treatment with paroxetine the patient completely resolved her depressive symptoms, and in parallel she did not worsen her cognitive status nor developed behavioural disorders. Therefore we concluded for a depressive disorder and we diminished our suspects for a prodromal dementia.